1. Field of the Invention
The present invention relates to a laboratory apparatus for a wet treatment of textile materials, including a specimen carrier being located in an exactly defined path of flow of a treatment liquid in a treatment chamber which in turn is integrated with a structural unit a conveying unit for the treatment liquid.
The application of such laboratory apparatuses is to examine and influence the physical and technical parameters of a treatment procedure by scientific methods prior to using such on a large technical scale.
2. Description of the Prior Art
A laboratory apparatus of the kind set forth above is disclosed the Swiss patent specification CH-PS 538 303 which apparatus comprises a treatment liquid conveying means which includes two conveying chambers which are open at two opposed sides and are closed towards the outside by two conveying membranes which are driven synchronously and oscillatingly in the same sense.
Such conveying means allows a circulating of the treatment liquid without any losses due to leakage and without contamination by particles produced by wear.
The design leads, however, positively to the pulsating flow of the treatment liquid which is unsatisfactory regarding a treatment procedure which should represent a realistically practical procedure for technically large scale operations.
Quite often, such test runs to not lend themselves to reproduction.
Furthermore, a reversing of the direction of flow of the treatment liquid is possible only by means of a additional use of a reversing valve which influences detrimentally the flow delivery capacity, the dead or clearance, respectively volume as well as the costs.
A further drawback is created by the fact that the delivery or conveying, respectively, capacity of such a conveying means--considering the small dimensions demanded in a laboratory--under certain conditions cannot satisfy the prevailing demands made. A mere enlargment of the conveying spaces leads additionally to a worsening of the base relation which contradicts again the desire of a laboratory apparatus which produces realistic and reproducible results.